Luvilla

Luvilla is a small, red demoness, born with a core of vileness in her chest

Luvilla is known for her mean personality, enjoying torturing others in sexually deviant ways and spouting many an insult.

The core of vileness is a family trait of hers, providing her her personality to a large extent. One could only imagine how she might behave if she didn't have that embedded in her sternum.